Development and realisation of a dynamic stand
on the basis of a industrial robot-manipulator

 

At designing of control systems (CS), including intelligent CS, labour-rent of CS elements in a structure of dynamic stands is important stage, as impossible to provide the given quality of CS functioning without undertaking a large volume of preliminary researches and tests. Under stand test occurs a characteristic study of different real equipment in sufficiently well controlled external environments with the conservation of the most important relationships of this equipment with other parts. The most significant factor for equipment, installed on the mobile object, is reproduction of the 6-extent space movements with the help of a stand. The robot-manipulator ("arm") RM-01 (also known as PUMA 560 - Programmable Universal Machine for Assembly), producing by industry, having necessary 6 degrees of freedom, is in essence suitable for creation of a appropriate stand. But herewith follows to point to the fact, primary 2-level arm CS "Sphere-36" (constructed on the basis of the specialized 16-bit minicomputer "Electronics H MC 11100.1", it is command compatible with DEC PDP-11) and arm kinematic scheme do not take into account completely specificity of of stand functioning (in particular, arm was initially capable to reproduce a trajectory of movement on beforehand known trajectory points only, i.e. perfect a movement from the point to a point), that has require a demanded change of a mechanical configuration and arm CS.

Thereby, contents of work is consideration of the proposals, connected with adapting an industrial robot RM-01 (PUMA 560) with reference to problem of reproduction 6-extent space movements.

The realization of control structure on the base of arm kinematic parities (ratio) is offerred at a stage of CS improvements, i.e. it's expect that desired movement is defined only by the kinematics, but influence of dynamic characteristics of drive with the load is insignificant. Control structure decides problems of integrating the kinematic equations of movement with using of known reference models and hard feedback compensating deviation between current variable and reference (i.e. tuning).
     The algorithms of stand are offered for different types of control: on velocities, on the position and generalise algorithm, which unites in itself value first two types of control and is kept new "kernel", builded on a linear programming problem deciding. These algorithms of stand were simulated with using of a MathWorks MATLAB 4.2, 5.1 and SIMULINK 1.2c, 2.1. Comparative testing have passed for continuous and exact reproduction by the arm spatial movement. The different structures and algorithms of servodrives connection were offered and proprototyped for reproducing the physical signals, calculated on digital computer by control algorithms.

The practical realization of the stand has demanded detailed studying of the available hardware and the organization of the direct access channel to the to the motor drives controller. The initial architecture originally has allowed to analyse an opportunity of using of the manual control board channel. It was found out, that hardware-software decisions incorporated in "Sphere-36" CS do not allow to achieve the necessary quality of stand functioning with such approach (it's impossible to control the six variable conditions simultaneously), therefore it was required to develop the hardware-software interface for control of the stand by using of the videoterminal channel. This decision supposes removed using of "Sphere-36" main element - Nokia ARPS (Advanced Robot Programming System) and its operating system ARPS/M B05.RM-01 for real time direct control of arm movement on the six degrees of freedom. All possibility of initial "Sphere-36" CS are saved and significant reserves for the further improvement of a stand are incorporated.

The initial RM-01 geometrical configuration has 3 singularity points and restrictions on degrees of mobility. In this connection the new variant of the kinematic scheme is offered, allowing to increase a range of arm movements and to get rid of most adverse singularity point. The mechanical improvement of arm design developed by students of IC-1 department A. S. Red'kin and O. V. Ryazanov during teaching projecting under supervision of V. N. Pivovarov, candidate of technical sciences, senior lecturer of RL-5 department. It is advanced and realized by the of RL-5 department employer E. M. Pavlov with participation of BMSTU experimental plant specialists.

 


We'll glad to see your opinion about this work:
Lobusov E. S.
Lonshakov A. V.
Goryachev M. L.
Kayutin I. S.

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